Building a Resilient Web Scraping Engine: Tiered Fallbacks, Fingerprint Spoofing, and SQLite Checkpoints

Description and use

An autonomous CLI engine for web scraping that uses fast HTTPX, escalates to stealth Playwright only when needed, and persists state in an ACID‑compliant SQLite database for resilience and resource efficiency.

Problem

Custom web scrapers often fail due to static request patterns, headless overhead, and volatile in‑memory state, leading to IP bans, slow throughput, and lost progress.

Outcome

The tiered engine achieves high throughput, reduces compute waste, and guarantees progress recovery, eliminating the need for paid extraction APIs.

Workflow

• Seed URLs into SQLite queue with statuses PENDING/IN_FLIGHT/COMPLETED/FAILED
• Tier 1: async HTTPX request with randomized User‑Agent and TLS spoofing
• Detect anti‑bot challenges (403/503/CAPTCHA/Cloudflare) and trigger escalation
• Tier 2: launch patched Playwright context, execute JS challenges, extract payload
• Atomic SQLite writes for checkpointing; resume on interruption without duplication
• Emit extracted JSON to Postgres or other sinks

Evidence

Firing 10,000 raw requests.get() calls with static User‑Agents results in an immediate IP burn or 403 Forbidden via Cloudflare Bot Management or Akamai.

Source

Running full Chromium instances for every single page request wastes compute, causes memory leaks, and slows down throughput by 800%.

Source

When an unhandled exception or 429 Too Many Requests crashes the process 8 hours into a 100,000-page crawl, developers without persistent state lose progress and re‑scrape identical records, burning proxy bandwidth.

Source